Ball-and-disk variable-speed mechanism.



A, H. POLLEN & H. ISHERWOOD. BALL AND DISK VARIABLE SPEED MECHANISM.APPLICATION FILED NOV. 5, 1912.

1,062,500. Patented May 20, 1913.

F/CJ. A 65 UNITED STATES PATENT OFFICE.

ARTHUR H. POLLEN, OF LONDON, AND HAROLD ISHERWOOD, OF YORK, ENGLAND.

-BALL-AND-DISK VARIABLE-SPEED MECHANISM.

To all whom it may concern Be it known that we, ARTHUR HUNGER- FORDPOLLEN and HAROLD IsHnRwooD, subjects of the King of Great Britain,residing at 14 Buckingham street, Strand, London, l/V. 0., England, andBishophill House, York, England, respectively, have invented certain newand useful Improvements in Ball-and-Disk Variable-Speed Mechanism, ofwhich the following is a specification.

This invention relates to an improved form of ball and disk variablespeed gearing in which the speed can be changed from Zero to a maximumspeed in either direction and can be varied smoothly through the wholerange.

The mechanism we employ consists of a horizontal disk which is caused torotate at a constant rate about a vertical axis by any suitable means.Above the disk are ar ranged two horizontal rollers equidistant from adiameter of the disk, and geared to rotate in the same direction at thesame speed. One of the rollers is keyed to the shaft to be driven at avariable speed, or if preferred the shaft on which that roller ismounted is geared to the driven shaft. The rollers are mounted in aframe adapted to slide horizontally on ball slides parallel to adiameter of the disk and in the direction of the axes of the rollers. Asteel ball rests on the disk below and between the rollers, the pressureto insure frictional contact be ing derived from a spring acting on aball thrust which forces the disk upward along its axis. The position ofthe ball on the disk is determined by the position of the aforesaidsliding frame, which when it moves through a given distance horizontallyrolls the ball along a diameter of the disk through a distanceapproximatelyequal to half the travel of the sliding frame. In order,however, to insure that the ball shall remain in its correct position itis embraced by a fork or its equivalent adapted to move parallel to themotion-of the sliding frame and driven thereby at the proper speed inrelation to the speed of the frame. Such a,

motion may be obtained from a pivoted lever acting on the fork at acertain distance fromthe pivot and which isacted on by the frame at agreater distance from the pivot. It will be seen that when the ball isin the center of its travel and coincides with the center of the disk,no rotation will be given to the rollers; but if Specification ofLetters Patent.

Application filed November 5, 1912.

Patented May 20, 1913. Serial No. 729,643.

the ball is displaced from such central position by a displacement ofthe sliding frame, the rollers will rotate with a speed directlyproportional to the magnitude and sign of the displacement of thesliding frame from its central position.

In order that the invention may be clearly understood we proceed todescribe the same with reference to the accompanying drawings in whichFigure 1 shows a side elevation of a mechanism constructed according tothis invention. Fig. 2 is a section on the line AB, Fig. 1 looking inthe direction of the arrows. Fig. 3 is a plan view of the ballcontrolling slide.

Referring to these figures 50 is a disk which is caused to rotate at aconstant speed about a vertical axis by means of suitable drivingmechanism such as the motor 3. The disk is carried on the cylindricalpiece 56 sliding in the sleeve 57 which is mounted on ball bearings 51,52 and is driven from the constant speed motor 3. The disk as a whole isforced upward by the spring 5-1 acting to press the cylindrical piece 56upward within the sleeve 57. Above the disk 50 which is made of hardsteel, is mounted a hard steel ball 60 which lies in contact with andbetween two rollers 61, 62 mounted in the frame 63. One of theserollers, in the present instance, the roller 62, is keyed to a shaft162, and this shaft thus constitutes the driven shaft, although ifpreferred it may have a suitable gear connection with the driven shaft.The frame 63 is capable of sliding as a whole as shown in Fig. 2 onballs 64 mounted in a race cut in the piece 65 which forms part of theframework of the mechanism. The spring 54 presses the ball 60 upwardagainst the rollers 61, 62 and maintains the frame 63 in contact withthe balls 64. In general the disk 50 is driven at a constant speed andcommunicates a variable speed to the ball 60 which in turn communicatesits speed of rotation to the rollers 61, 62 and thence to shaft 162 orto the shaft with which shaft 162 has a gear connection. Inorder tocause the displacement of the ball radially on the disk 50, the frame 63carrying the rollers 61, 62 is shifted as shown in Fig. 2. In this waythe position of the ball on the disk is determined by the position ofthe sliding frame 63 which when it moves through a given distancehorizontally rolls the ball along a diameter of the disk through adistance approximately equal to half the travel of the sliding frame. Inorder however to insure that the ball shall remain in its correctposition it is embraced by a fork 66 carrying rollers 67 arranged tomove parallel to the sliding frame and driven thereby at the properspeed by means of the levers 6S pivoted about the fixed centers 69 andprovided with slots in which the pins 70 carried by the sliding frame 63and the pins 71 carried by the fork 66 engage. In general a constantspeed is communicated to the disk and a variable speed is taken out fromthe rollers, but in some cases this disposition is reversed and therollers drive the disk. Any suitable means may be adopted for shiftingthe frame 63 which carries the rollers 61, 62, for producing the desiredchanges of speed. The means shown in the drawings consist of a rack 23mounted on the frame 63 driven by the pinion 24L mounted on the shaft25. The advantage of this construction is that owing to the changes inthe balls position being produced by a rolling action, the ball does notslip or fail to drive the rollers at the moment when its position isbeing changed. This was formerly a difficulty which introduced anoticeable inaccuracy in the earlier forms of disk and rollervariable-speed gearing.

lVhat we claim is 1. Variable-speed mechanism comprising a drivingelement, a driven element, a steel ball intermediate said elements andin frictional contact with one of them, a fork carrying said ball, amember connected rotatably to the other element and contacting with saidball, a frame wherein said member is carried, means to displace saidframe so as to travel said ball radially relatively to the element withwhich it frictionally contacts, and means to produce the requisitedegree of frictional contact between said ball and that element.

2. Variable-speed mechanism comprising, a driving element, a drivenelement, a steel ball intermediate said elements and in frictionalcontact with one of them, a fork carrying said ball, a pair of rollersmounted above said ball and contacting therewith, a frame carrying saidpair of rollers, means to displace said frame so as to travel said ballalong a diameter of the element with which it frictionally contacts,said fork constraining said ball to travel a distance equal pair ofrollers mounted above said ball and contacting therewith, one ofsaidrollers being keyed to said shaft, a frame carrying said pair ofrollers, ball-slides supporting said frame, means to displace said framelongitudinally of saidball-slides so as to travel said ball along adiameter of said disk, said fork constraining said ball to travel adistance equal to half the distance traveled by said frame, and means toproduce the requisite degree of frictional contact between said ball andsaid disk.

4:. Variable'speed mechanism comprising -a horizontal driving disk, adriven shaft, a

steel ball intermediate said disk and said shaft, said ball being infrictional contact with said disk, a fork carrying said ball, a pair ofrollers mounted above said ball and contacting therewith, one of saidrollers being keyed to said shaft, a frame carrying said pair ofrollers, ball-slides supporting said frame, means to displace said framelengthwise of said ball-slides in a direction at right angles to theaxes of said rollers so as to travel said ball along a diameter of saiddisk, means connecting said fork with said frame to cause the fork tomove parallel to the direction of motion of the frame, said forkconstraining said ball to travel a distance equal to half the distancetraveled by said frame, and means to produce the requisite degree offrictional contact between said ball and said disk.

In testimony whereof we have hereunto set our hands in presence of twosubscribing witnesses.

ARTHUR H. POLLEN. HAROLD ISHERWOOD.

Witnesses as to the signature of Arthur H. Pollen:

F. H. POLLEN, E. O. WALKER.

WVitnesses as to the signature of Harold Isherwood:

B. R. ATTENBOROUGH, S. MA'rrHEws.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. G."

